基于有限元模拟的铸旋轮毂内轮缘部位旋压成形分析

针对A356铝合金铸旋轮毂旋压成形中出现的内轮缘部位力学性能不足的问题,基于有限元模拟的方法对内轮缘部位的旋压成形过程进行了研究分析。为了得到有限元模拟用的材料参数,在A356铝合金铸旋轮毂的铸坯上取样,在温度为360℃且应变速率为0.0001~0.1 s-1的条件下进行高温拉伸试验。使用Abaqus软件建立了轮毂旋压过程的模型,分两步分析了旋压过程中内轮缘部位的成形过程。研究了工艺参数中旋压进给量和摩擦系数对内轮缘部位等效应变的影响规律。模拟结果为优化力学性能、改善工艺参数提供了依据。     

一种铝合金轮毂铸旋成形工艺

介绍了铝合金轮毂铸旋成形工艺技术,铸旋工艺能够满足铝轮毂的高强度、轻量化要求,是未来铝合金轮毂工艺发展的主要方向之一。从铸旋生产背景、流程、铸旋工艺原理方面进行了介绍,并着重对影响旋压工艺的多种因素、参数设置及工艺优化进行了重点分析和说明,为铸旋成形工艺的研究提供了参考方向。     

铸旋轮毂热旋压过程的数值模拟及工艺优化

为了优化铸旋铝合金轮毂的生产工艺,基于旋压变形的特点,建立了铸旋铝合金轮毂三旋轮热旋压复杂过程的三维有限元模型。采用所建立的有限元模型对实际的A356合金轮毂铸坯热旋压过程进行了数值模拟,对旋压载荷进行了分析,为旋压设备的选择和模具设计提供了依据;同时研究了铸坯开口角和旋轮轨迹分别对轮辋和内轮缘处应变分布的影响规律,获得了合理的开口角度和优化的旋轮轨迹。     

铸旋轮毂内轮缘部位数值模拟及工艺优化

针对A356铝合金铸旋轮毂旋压成形中出现的内轮缘部位机械性能不足的问题,基于数值模拟方法对内轮缘部位旋压成形过程进行研究分析。通过温度为300~375℃,应变速率为0.0001~0.1 s~(-1)的高温拉伸实验,得到数值模拟中所需的材料参数。运用Abaqus软件建立不同芯模的轮毂旋压模型分析内轮缘部位的成形过程并进行了相应的实验验证。内轮缘部位的旋压成形数值模拟与成形件的微观组织形貌分析结果表明,几种不同的芯模旋压模型中,斜面模型的整体变形量和变形均匀性要远大于原始模型,圆弧模型次之。不同芯模结构和旋轮进给路径对内轮缘部位的影响规律的分析结果,为优化机械性能、改善工艺参数提供了依据。     

5A06铝合金壳体热旋成形工艺研究

对5A06铝合金曲母线型壳体开展了厚壁板材两次加热剪切旋压、成品加热普旋成形的成形工艺研究,分析了坯料加热温度、旋轮几何形状及参数、旋压道次、旋压进给方向、旋轮进给比、壁厚减薄率等工艺参数对5A06铝合金壳体旋压成形的影响规律,研究了旋压过程中材料出现的破裂、起皱、扭曲、扩径等现象并提出了解决措施,辅以精密整形和热处理工序,研制了几何尺寸和机械性能均满足要求的5A06铝合金曲母线型壳体,为类似形状制件的旋压成形提供了参考。     

A356铝合金轮毂铸旋新工艺的应用与毛坯设计

阐述了铝合金轮毂铸旋新技术的应用及发展,制定了铝合金轮毂铸旋新工艺的工艺流程并介绍了其工艺原理。结合轮毂轮辋旋压变形过程,通过实物设计和分析,提出了铸旋铝合金轮毂毛坯的设计流程,确定了设计前后的体积比为(1.03±0.1)∶1,制定了旋压前毛坯造型的设计规范。铝合金轮毂铸旋新工艺综合了低压铸造和旋压加工的优点,极大地提高了轮毂的精度、强度。     

耐热粉末铝合金筒体热旋成形试验

介绍了喷射沉积耐热铝合金管坯经挤压变形,变薄旋压筒体的研制过程;重点论述了热旋成形筒体的工艺路线。试验探讨了耐热铝合金的旋压温度为350－450℃,道次变薄率约为20％,累计变薄率约50％,需中间退火,退火温度宜取350℃。热旋结果认为,喷射沉积耐热粉末铝合金铸坯直接热旋成形困难,需经挤压比大于4的变形致密,有助于热旋成形。耐热粉末铝合金挤压坯加热变薄旋压,应采用小压下量多道次的变形过程,逐渐细化晶粒组织,才能旋出综合性能良好的筒形件。     

高性能A356铝合金轮毂开发技术研究进展之二——轮毂成形强化技术

针对高性能大尺寸A356合金轮毂开发所涉及的轮毂成形工艺和热处理强化环节的研究进行了总结。介绍了铝合金轮毂的各种成形强化工艺,并进行了对比。最后,阐述了铝合金轮毂新强韧化的一些关键性技术,如共晶相脆性特征改善、沉淀相调控等,并给出了相应的理论解释。     

先进的铝合金轮毂旋压成形技术

铝合金轮毂旋压技术是近几年才发展起来的车轮成形新工艺方法。文章详细阐述了以板材、管材、预制锻坯等为坯料生产铝合金轮毂的旋压成形工艺,旨在推广旋压技术的应用,促进铝合金轮毂制造业的发展。     

两旋轮旋压首道次压下率对轮毂旋压成形的影响

针对低压铸造A356铝合金轮毂的两旋轮旋压成形特点,通过旋压成形数值模拟及实验分析了在两旋轮旋压工艺下首道次压下率对轮辋壁厚均匀性、 坯料隆起高度、 旋轮所受压力以及轮辋微观组织与力学性能的影响.结果表明,当首道次压下率为40％时,轮辋壁厚较均匀,成形质量较好,坯料隆起高度较小,材料贴模性较好,两个旋轮所受压力较稳定,...     

低过热度铸造和触变锻造结合制备A356铝合金车轮的组织与力学性能

采用低过热度铸造和触变锻造相结合的方法制备A356铝合金车轮,研究低过热度铸造A356铝合金坯料的组织、坯料二次加热组织演变规律和触变锻造车轮的组织与力学性能。结果表明：熔体在635℃浇注,可获得具有细小、均匀的非枝晶晶粒的A356铝合金坯料。坯料在600℃等温加热60min后,非枝晶晶粒可转变成球形晶粒,在750kN锻压力下半固态坯料可触变锻造成铝合金车轮。经T6热处理,A356铝合金车轮的抗拉强度和伸长率分别为327．6MPa和7．8％,高于铸造铝合金车轮的拉伸力学性能。将低过热度铸造与触变锻造工艺相结合,可以制备具有较高力学性能的铝合金车轮。     

热处理工艺对6061铝合金筒形件旋压过程及其性能影响

为满足某6061铝合金筒形件产品较高的形状、尺寸精度及机械性能要求,对热挤压态6061铝合金管坯件旋前不同热处理工艺规范(退火、固溶、不完全退火和半同溶)进行了分析比较,研究获得不同热处理工艺规范对旋压成形过程及其性能的影响规律.结果表明,对热挤压态6061铝合金管坯件而言,在旋压成形前进行半固溶处理(即将管坯加热到4...     

Process Modeling of Low-Pressure Die Casting of Aluminum Alloy Automotive Wheels

Although on initial inspection, the aluminum alloy automotive wheel seems to be a relatively simple component to cast based on its shape, further insight reveals that this is not the case. Automotive wheels are in a select group of cast components that have strict specifications for both mechanical and aesthetic characteristics due to their important structural requirements and their visibility on a vehicle. The modern aluminum alloy automotive wheel continues to experience tightened tolerances relating to defects to improve mechanical performance and/or the physical appearance. Automotive aluminum alloy wheels are assessed against three main criteria: wheel cosmetics, mechanical performance, and air tightness. Failure to achieve the required standards in any one of these categories will lead to the wheel either requiring costly repair or being rejected and remelted. Manufacturers are becoming more reliant on computational process modeling as a design tool for the wheel casting process. This article discusses and details examples of the use of computational process modeling as a predictive tool to optimize the casting process from the standpoint of defect minimization with the emphasis on those defects that lead to failure of aluminum automotive wheels, namely, macroporosity, microporosity, and oxide films. The current state of applied computational process modeling and its limitations with regard to wheel casting are discussed.     

轮毂闭式反挤压成形工艺研究

汽车轻量化是世界汽车发展大趋势.试验证明,汽车整备质量每减少100kg,百公里油耗可降低0.3～0.8L.目前大部分汽车安装的轮毂为铸造铝合金轮毂(以乘用车为主)或钢质车轮(以商用车为主).锻造铝合金轮毂重量比铸造铝合金轮毂的重量轻10％左右,比钢质轮毂重量轻2/3左右.因此,采用锻造铝合金轮毂符合汽车轻量化发展的大趋...     

铝合金形变热处理工艺参数及其控制

如何正确地选择和控制工艺方案及其参数,是影响铝合金形变热处理效果的一个关键因素.为了使铝合金形变热处理工艺发展到恰当的、合理的程度,适合工程的需要,获得优良的形变强韧化效果,作者在文中分析了形变热处理的主要工艺参数及其控制.     

Hot shear spinning of cast aluminium alloy parts

A hot shear spinning process of cast aluminium alloy parts was developed to eliminate casting defects and to obtain a desired distribution of wall thickness. The forming load of the shear spinning is comparatively low even for large deformation requisite for eliminating the casting defects. Dendrites and shrinkage cavities in the cast aluminium alloys were successfully eliminated without occurrence of a fracture by the hot shear spinning. Surface cracks around the corner of the mandrel caused by large shear deformation were reduced by decreasing the feed rate of the roller and by increasing the tip radius of the roller. It was found that hot shear spinning is effective in improving the mechanical properties of cast aluminium alloys parts.     

Evolution of microstructure and mechanical properties of A356 aluminium alloy processed by hot spinning process

The evolution of microstructure and mechanical properties of A356 aluminum alloy subjected to hot spinning process has been investigated.The results indicated that the deformation process homogenized microstructure and improved mechanical properties of the A356 aluminum alloy.During the hot spinning process,eutectic Si particles and Fe-rich phases were fragmented,and porosities were eliminated.In addition,recrystallization of Al matrix and precipitation of AlSiTi phases occurred.The mechanical property testing results indicated that there was a significant increase of ductility and a decrease of average microhardness in deformed alloy over die-cast alloy.This is attributed to uniform distribution of finer spherical eutectic Si particles,the elimination of casting defects and to the recrystallized finer grain structure.     

铸造钛合金管坯的旋压成形及性能研究

研究了某铸造钛合金管件的旋压成形工艺,探讨了该钛合金热旋压过程常见缺陷产生的原因,对旋压件组织和力学性能进行了分析.结果表明:该铸造钛合金在一定的旋压条件下具有较好的可旋性,旋压后铸态晶粒被压扁拉长,形成明显的纤维组织,减薄率超过72＆时,铸态组织基本消除.旋压后材料强度和塑性指标均有所提高.